const o = {a:1}
const px = new Proxy(o, {
  get(target, p, receiver) {
    console.log('get~~~~~~');
  },
  set(target, p, value, receiver) {
    console.log('set~~~~~~')
  }
});

px.a = 123 // 'set~~~~~~'
/** ↑这种情况下,px.a不会触发get,只会触发set*/

px.a //'get~~~~~~'
/** ↑但这样会触发get*/

